Jy997 d22101 b[1]

Your First PLC
Learning by Relay Sequences...
Introduction

Safety Precautions
(Be sure to read this before the training.)
Before designing a system, be sure to read this manual and pay close
attention to safety.
During the training, pay attention to the following points to ensure
correct handling.
To prevent electric shock, do not touch the terminals while they are
powered ON.
Before removing safety covers, either turn the power supply OFF or
confirm safety.
Do not put your hand into moving parts.
[Precautions for Training]
DANGER
Proceed with the training under the guidance of a teacher.
Do not remove the training machine module or change the wiring
without permission. Doing so may result in malfunction, misoperation,
injury or fire.
Before attaching or detaching the module, turn the power OFF.
Attaching or detaching the module while it is still ON may cause the
module to malfunction or cause an electric shock.
If unusual odor is detected with the training machine (X/Y table, etc.)
immediately turn the power switch to OFF.
If an abnormal event occurs, immediately contact your teacher.
CAUTION

This text book introduces basic knowledge you should be aware of for
sequence control together with simple examples for first-time users of
PLCs.
Descriptions in this text book are primarily for the teaching material FX-I/O
demonstration model that uses the micro PLC FX1S-14MR type.
The following shows related materials:
(1) FX1S Hardware Manual ⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ JY992D83901
(2) FX Programming Manual
(FX1S, FX1N, FX2N, FX2NC) ⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ JY992D88101
(3) FX-10P Operation Manual (Operation Procedures)
⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ JY992D33401
INTRODUCTION
This document does not guarantee the implementation of industrial
copyright and other rights, nor authorizes rights of implementation.
Also, MITSUBISHI ELECTRIC CORPORATION cannot assume any
responsibility whatsoever for problems in terms of industrial copyright
that may arise by use of the content described in this document.
© 2006 MITUBISHI ELECTRIC CORPORATION
1

1.1 What Is "Sequence Control?" ⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 4
1.2 Devices Associated with Sequence Control ⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 6
1.3 Items Required for Sequence Control ⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 8
1.4 Performing Wiring Based on Sequences ⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 11
1.5 Let's Remember Sequence Symbols ⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 16
2.1 What is a "PLC?" ⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 18
2.2 How PLCs Work ⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 19
2.3 Wiring and Programs ⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 23
2.4 Advantages of Using PLCs ⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 24
4.1 Introductory Example 1 (Control of Escalators) ⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 43
4.2 Introductory Example 2 (Control of Tea Dispenser) ⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 45
4.3 Introductory Example 3 (Control of Drilling Machine) ⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 47
4.4 Introductory Example 4
(Control of Quiz Answer Display Panel) ⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 49
Appendix 1 The OPERATION OF THE GX Developer ⋅⋅ 51
Appendix 2 SFC Program Outline ⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 99
Appendix 3 Training Machine's I/O wiring Example ⋅⋅⋅⋅⋅ 101
3.1 Let's Remember PLC Instructions ⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 28
LD, LDI, OUT, END
SET, RST
AND, ANI
OR, ORI
ANB
ORB
NOP
3.2 Order of Programs ⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 38
3.3 About Timer Circuits ⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 39
3.4 About Counter Circuits ⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 40
3.5 About Self-hold Circuits ⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 41
Chapter 1 WHAT IS "SEQUENCE CONTROL?"
Chapter 2 WHAT IS A "PLC?"
Chapter 3 SEQUENCE INSTRUCTIONS
Chapter 4 PROGRAM TRAINING
Appendices
Contents
2

Let's Learn About Sequences
3
Let's learn about sequence control
Sequence control is a word that we ordinarily do not hear often. Yet, it exists all
around us and we have contact with it in our day today lives.
For example, a fully automatic washing machine is an excellent example of
"sequence control."
In this chapter, we will consider what "sequence control" is and the affect it has
on our daily lives.
WHAT IS "SEQUENCE CONTROL?"
Chapter 1

4
1.1 What Is "Sequence Control?"
What does "sequence" mean?
Though the word "sequence control" may generally be unfamiliar to us, it is used
very often around us, and everyone is likely to have seen or have had contact
with something that is controlled by sequence control.
Dictionaries describe the word "sequence" as follows:
From this, we can understand that "sequence" refers to a succession or order in
which events occur.
Examples of things you are familiar with
Let's consider an example of a car wash you frequently catch sight of at a gasoline stand.
(1) State or fact of being sequent or consequent
(2) Succession
(3) Order of succession
(4) A series of things following in order, etc.
Putyourmoneyinandpress
theSTARTbutton.
Thecarisfirstwashedwith
water.
Dirtandmudisthenremoved
fromthecarwithdetergent.
Brushedwithabigrotating
brush.
Andthenwashedagainwith
water.
Waterisbrushedoffthecar
andthecarwashiscomplete.
Sequence

5
Though operation of the car wash on the previous page was described in
approximate terms, this order is the basic way of thinking behind sequences, and
making this sequence operate correctly and automatically countless times as
intended becomes sequence control.
Sequence control is used extensively and is a vital approach in all situations and
all fields.
Sequence control is used not just in complex applications but also in applications
very familiar to us.
Household electrical appliances Elevator
Factory
Power substationsAutomatic vending machines
Sequence control is usedin a wide range of fields.

6
1.2 Devices Associated with Sequence Control
Component devices in sequence control
The following devices are used to perform sequence control.
These devices can be broadly classified as follows:
"devices operated by personnel"
"devices that notify personnel of machine states"
"devices that detect machine states"
"devices for making machines move"
Various devices are also combined to perform sequence
control in a car wash, for example.
Devices for making machines move
Devices operated by personnel Devices for detecting machine states
Start/stop buttons, etc.
Devices for notifying personnel of machine states
In-operation lamps, etc.
Switches, etc. for detecting arrival of vehicle
Personnel
Devices operated by personnel Devices for notifying personnel of machine states
Switches, etc. Lamps, buzzers, etc.
Pumps for discharging
detergent or water, and
motors, etc. for rotating
brushes
Start
Stop
Sequence

7
The devices shown in this figure are just examples and only a few of many such
devices.
In sequence control, combinations of devices such as these are made to operate
in accordance with a work procedure.
Of these devices, "devices operated by personnel" and "devices for detecting
machine states" become the conditions for making things move in sequence
control, while "devices that notify personnel of machine states" and "devices for
making machines move" are the devices that are operated in accordance with
these conditions.
Operation panel ⋅⋅⋅⋅⋅⋅ A panel on which "devices operated by personnel"
(pushbutton switches, selector switches, etc.) and
"devices for notifying personnel of machine states"
(lamps, digital displays, etc.) are installed.
Control panel ⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ A panel on which devices, such as electromagnetic
contactors, relays and PLCs, for controlling machine
movement, are installed.
Magnetic contactors, relays, etc.
Devices for detecting machine states Devices for making machines move
Machine
Limit switches, proximity switches, etc. Motors, solenoid valves, etc.
Though small-load devices such as
small-size solenoid valves and pilot
lamps can be driven directly by a PLC,
large-load devices such as large-size
solenoid valves must be driven via an
electromagnetic contact or relays.
Control

8
1.3 Items Required for Sequence Control
Let's actually consider sequence control.
Now, let's try actually considering sequence control based on the connection
diagram below. The following also describes the terms you need to know in
learning sequence control.
The electrical circuit below is wired using a pushbutton switch and
lamps (blue, red).
Content of sequence control
(1)When the pushbutton switch is not pressed, electricity flows along route B
and the blue lamp is lit.
(2)When the pushbutton switch is pressed, electricity flows along route A and
the red lamp lights.
(3)When the pushbutton switch is released, the blue lamp lights again as in (1) above.
The operations in (1) through (3) are part of sequence control.
Example 1
Connection diagram
Pushbutton
Blue lamp
Red lamp
Relay
Power supply

9
Let's learn some new terms.
The following describes the relay on the page on the left.
About relays
A relay is a simple electromechanical switch made up of an electromagnet and
a set of contacts .
About contacts
Where are relays used?
(1) Relays can make large motors and lamps operate by using small signals.
(2) Relays can make motors and lamps in remote sites operate.
Relay Cross Section
Moving contact Moving contact
Fixed contact
12VDC(direct current)
100VAC(Alternate currect)
Magnet
Flow of
electricity
Magnet
When electricity flows to
the magnetic, the moving
contact is actuated.
A "contact" is a contacting part that performs switching operation, and
allows electricity to pass or blocks electricity. Other forms of contacts were
found in switches, timers, counters and other devices. There are two types
of contacts, N.O. contacts and N.C. contacts. (See next page)

10
About contacts
Contacts perform a switching operation to block electricity or make parts conduct.
Basic contacts are N.O. contacts and N.C. contacts, and switches, relays,
timers, counters and other devices have contacts.
A "N.O. contact" is a "normally open" contact, and closes when an instruction
(Note 1) is made to the contact.
A "N.C. contact" is a "normally closed" contact, and opens when an instruction is made.
Pushbutton
Pushbutton
Moving contact
Moving contact
Moving contact
Moving contact
Press button
Press button
Fixed contact
Fixed contact
Fixed contact
Flow of
electricity
Flow of
electricity
Fixed contact
Wiring
Wiring
WiringWiring
Circuit
closed
Circuit
open
Wiring
Contact
Wiring
Spring
Spring Spring
Before button is pressed (in return position) After button is pressed (in operating position)
Spring
Circuit
open
Note 1 An "instruction" here means "causing an operation or change." The operation of
pressing a pushbutton corresponds to an instruction.
N.O. contacts
N.C. contacts
Operation: In the case of a pushbutton switch
When the pushbutton switch is not pressed, the contact is open.
When it is pressed, the contact closes.
Operation: In the case of a pushbutton switch
When the pushbutton switch is not pressed, the contact is closed.
When it is pressed, the contact opens.

11
Red lamp
Blue lamp
Relay
Figure 1.Blue lamp
Figure 2.Red lamp
Wiring diagram
Red
Lamp 1
Lamp 1
Common contact N.C. contact Relay
Coil
Pushbutton
Pushbutton switchN.O. contact
Lamp 2
Lamp 2 24VDC power supply
Blue
Red
Lamp 1
Lamp 1
Coil
Pushbutton
Lamp 2
Blue
Pushbutton
DC power supply
Product configuration
1.4 Performing Wiring Based on Sequences
Now that you've learned some new words
Let's train using Example 1 on page 1-6
that we studied for relay contacts.
Outline of relay-wired training
demonstration model
Power cable 1 pc
Pushbutton 1 pc
Blue lamp 1 pc
Red lamp 1 pc
Relay 1 pc
Wires (brown, red, orange, yellow,
green, blue, purple, gray) 1 each
Note) In this example, power supply terminals
No.4 and No.5 are common terminals.
2 What is an "actual wiring diagram?"
Let's wire the training demonstration model.
1. Make sure that the training
demonstration model is turned OFF.
2. Wire the blue lamp in Figure 1 by
connecting the wires as follows:
Purple wire to No.7 terminal
Yellow wire to No.4 terminal
Gray wire to No.8 terminal
3. Wire the red lamp in Figure 2 by
connecting the wires as follows:
Green wire to No.5 terminal
Blue wire to No.6 terminal
Brown wire to No.1 terminal
Red wire to No.2 terminal
Orange wire to No.3 terminal
This refers to a diagram that is as close
as possible to the real thing and that
shows circuit connections and devices
used for the circuit. As wiring and the
structure of devices can be accurately
seen in this diagram, it is handy when
actually manufacturing devices or
performing maintenance.
2

12
Now that you've learned some new terms and phrases
Let's check operation
Let swap the content of sequence control explanation on page 1-6 with the new
terms and phrases you've learned.
(1) When the power is turned ON, the N.C. contact and route B is made , and the
blue lamp is turned on.
(2) When the pushbutton switch (N.O contact) is pressed, the action of the relay
causes the N.O. contact to close. Route A is made , and the red lamp is turned on.
(3) When the pushbutton switch is released, the blue lamp is turned on again as in (1)
above.
What is a "flow chart?"
With sequence control, various devices are combined to comprise a circuit. To
explain, the control of these devices can become quite difficult using based
methods. Therefore a flow chart is a preferred method for explaining a control
sequence.
A flow chart uses rectangular symbols and arrows to more simply express the
overall order of related operations.
What is a "time chart?"
A time chart expresses changes in the operation sequence over time.
The devices to be controlled are drawn on the vertical axis, while changes over
time are drawn on the horizontal axis. Dotted lines with arrow heads are used to
show the relationship between respective devices and resulting operations.
Time charts sometimes express changes over time without the use of arrows.
You can also learn the content of sequence control from flow charts and time charts.
p
Sequence expressed as a flow chart
Sequence expressed as a time chart
Power ON
Blue lamp Lit
Red lamp Out
Blue lamp Out
Red lamp Lit
Pushbutton
switch pressed?
Pushbutton
switch not
pressed?
NO
Pushbutton
Relay
Pressed Released
Blue lamp
Red lamp
Pushbutton
NO
YES
YES
Closed
Operating
Lit
Lit Lit
Relay

13
An actual wiring diagram is a diagrammatic means of making the structure of devices
and wiring easy to understand. However, the operation sequence is harder to follow
in actual wiring diagrams for complex electrical circuits.
Let's try swapping an actual wiring diagram with a sequence diagram to illustrate this point.
Sequence diagrams are connection diagrams intended to make the content of
operation of many circuits easier to understand. Unified standards enable this
diagrammatic method to be easily understood by third parties.
Note) With the FX-I/O demonstration
training machine, both relays
and lamps are driven by a
24VDC power supply. However,
in general, relays are driven by
a 24VDC power supply and
lamps are driven by a 100VAC
power supply. This is shown in
the figure below.
Lamp 1
Lamp 1
Coil
Pushbutton
Lamp 2
Actual wiring diagram and sequence diagram
6
7
8
8 3
4 4 5 7 1
1
2
26
35
Wiring Diagram
Sequence Diagram
DC power supply
PB
RELAY
Pushbutton switch Relay coil
RELAY (N.C. contact)
Blue
BLUE
RED
Red
RELAY (N.O. contact)
AC power supply

14
Let's consider another example
Transfer pump
Pump
Well
Full
LS1OFF
LS2OFF
Operation
Stop
Motor
Empty
Water
level
Tank
LS2 (N.C. contact)
Float switch turns OFF
when tank is full.
LS1 (N.O. contact)
Float switch turns ON
when tank is empty.
Controlling the level of water in a tank
Details of sequence control
(1) When the operation switch is closed, the float switch limit switch 1 closes if
the tank is empty, and the magnet switch MC is operated to drive the transfer
pump motor.
Relay MC is designed to hold its own state even if the water level is at the mid
position.
(2) When the tank becomes full, float switch limit switch 2 opens, hold operation
of the relay MC is canceled, and the transfer pump motor stops.
(3) When the water level reaches the empty level, the motor starts to operate
automatically again.
With motor operation in this control
example, the motor starts to operate at
the mid position after an empty tank is
detected.
Motor operation stops at the mid
position after a full tank is detected,
and the motor operating state differs
even at the mid position.
This kind of operation is called
"hysteresis operation" and can reduce
the number of times that motor
operation is stopped.
Example 2
LS1ON
LS2ON

15
Motor
power
supply
MC
Control power supply
Start switch
The start switch
stays ON even
if it is released.
(residual operation
type)
LS2 3 LS1
MC
1
M Motor
Contacting of the relay
drives the motor.
MC
Breaker
Start switch
Full Full
Water level mid position
Water level
mid position
Float switch
LS2
Float switch
LS1
Magnet
switch
The sequence in this section is generally replaced by a sequence program on a PLC.
About self-hold circuits
A "self-hold circuit" refers to an operation circuit that bypasses signals
arriving from an external relay or other device by means of the contact of
the relay itself.
Self-hold circuits can also be said to have a memory function that allows
them to operate continuously even if the circuit is cut by releasing a pressed
pushbutton.
In this circuit, the contact of the relay (MC ) for driving the motor is
connected in parallel to float switch limit 1 (LS1). This provides an example of
a "self-hold switch."
Though limit switch 2 (LS2) functions to cut the self-hold circuit to stop the
transfer pump motor, when limit switch 2 (LS2) is used with a N.C. contact, the
switch can also be turned OFF to stop transfer of water during a switch contact
failure or wiring break.
Sequence diagram
Operation of self-holding circuit (time chart)
Breaker This device breaks the
circuit for the current when
an abnormal current flows.
1
2
3
MC 2
N.O. contact The float switch turns ON
when the tank is empty.
Magnet
switch
N.O. contact
The float switch
turns OFF when
the tank is full.
N.C. contact
Water level mid position
Empty
Operation
Even when the float
switch LS1 turns OFF,
operation of the magnet
switch continues due to
the self-holding circuit.
2

1.5 Let's Remember Sequence Symbols
List of main sequence symbols
JIS C0617
Drive Source
Manual
Manual
Heater
Operation
Manual
Dog cam
Electromagnetic
coil
N.C. ContactN.O. ContactContact Category
Horizontal formatVertical formatHorizontal formatProduct Category
Pushbutton
switch
(Auto-
return type)
Pushbutton
switch
(residual
operation type)
Thermal
relay
(OCR)
Limit
switch
(general)
Limit
switch
(mechanical
operation)
Auxiliary
switch relay
contact
Magnetic
contactor
Timer
ON delay
Timer
OFF delay
Vertical format
16

Introducing You to PLCs
17
What is a "PLC?"
PLC stands for "programmable controller" and is sometimes known as a
"sequence controller" or SC. These are defined as electronic devices that
control various devices via I/O sections and have built-in memory for
storing programmable instructions.
Actually
So far, we have performed "sequence control" by physically wiring relays
and timers. This chapter considers the use of a simple PLC program to
control electronic devices.
WHAT IS A "PLC?"
Chapter 2

18
2.1 What Is a "PLC?"
What do PLCs do?
Personnel
Switch, etc. Lamps, buzzers, etc.
Sensors, etc. Motors, solenoid valves, etc.
Devices for notifying personnel
of machine states
Devices operated
by personnel
Sequence control
Devices for making
machines move
Machine
Devices for detecting
machine states
The devices that are operated by personnel or that detect machine states in
sequence control are called "instruction signals" or "condition signals."
Devices that notify personnel of machine states or that move machines are
called "loads."
PLCs are responsible for carrying out "sequence control." The diagram above
illustrates the control of these devices. Where the condition signals and loads in
the devices are connected to the PLC.

19
2.2 How PLCs Work
How does sequence control work?
PLCs are microcomputer-controlled devices for industry.
Devices connected to the input side of the PLC are called "input devices," while
devices connected to the output side of the PLC are called "output devices."
One device is connected to each terminal block.
One input device and one output device may merely be connected to a PLC in
this way, and the connection for performing sequence control is performed
electronically inside the PLC.
PLC internal connections are programmed using dedicated sequence language
(instructions), and a combination of these instructions is called a "sequence
program." Sequence control is performed in accordance with this program, so
there is no need to wire externally.
Limit switches
Relay contact
Select switch
Pushbutton switch
PLC
Input Devices
Programming
panel
Power supply
Outputinterface
Inputinterface
Storage
section
Operation
section
Memory
Microcomputer
Contactor
Lamp
Solenoid valve
(solenoid valve)
Output Devices
Power supply

20
Actually consider a PLC as a group of relays and timers
The figure above shows how the input devices, output devices and the sequence program are configured.
The input devices is connected to the PLC's input relays, and the output device is controlled via contacts for external outputs.
Input relays
Output contacts
The input relays convert the signals from an external device to signals for the
PLC. In the above figure, the input device is designed to operate merely by
connecting across the input terminal and the COM terminal.
However it should be noted that PLCs have a limited number of contacts, even
though, an infinite number of contacts is provided on the sequence program.
The PLC has a built-in power supply
for the input relays. When the
contact of the input device is
conducting, current flows along the
dotted line to drive the input relay.
When the output relays on the
sequence program are driven, the
contacts for external output close.
Provide a power supply for driving
the external device outside the PLC.
Regardless of whether the external input device is a N.O. contact or a N.C.
contact, the contact on the PLC that closes when the COM and input terminals
are conducting is an N.O. contact, and the contact that opens is a N.C. contact.
Output contacts are otherwise known as just outputs. These are coutrolled by
the sequence program, and are necessary for driving an external load.
Devices having a different power supply (AC or DC) can be connected to the
contacts for external output.
Input relays operated
by external signals
Sequence program operated
by input relay contacts
Output of output
relay operation
External load
operated
Power
supply
Output relays
Timers
Auxiliary relays
Contacts for
external outputs
Input relays
PLC
Operation
Operation
PB1
LS1
PB2
X001
Y000
X001
X005
M100
X007
K100
X003
Output relays
Timers
Auxiliary relays
COM
X000
X001
X002
X003
X004
X005
X006
X007
X001
X003
X005
M100
T 0
Y100 Y000
Y001
Y002
Y002
Y000
Y000
PL
MC
Y001
Y001
Y002
Y003
Input device
COM
Input relay
PLC
Input terminal
COM
PLC
Output device
Power supplyContacts for external outputs
Output terminal

21
An I/O number is assigned to each terminal to make the I/O devices connected
to the input terminals and output terminals correspond to the input relays and
output relays of the sequence program.
Timers and counters held internally by the PLC are also assigned to devices
numbers in addition to each terminal number.
Element numbers ⋅⋅⋅⋅⋅⋅ Element numbers comprise a symbol that shows what the
devices is and a number that categorizes individual devices.
Input relays act as the "point of contact" for
receiving signals, for example, from an input
switch outside of the PLC. X is used to
identify their device number. PLCs have a
built-in number of input relays corresponding
to the number of inputs (number of terminals).
Input relays : X000~
Output relays act as the "point of contact" for
driving loads outside the PLC. Y is used to
identify their device numbers. PLCs have a
built-in number of output relays corresponding
to the number of outputs (number of
terminals).
Output relays : Y000~
Timers are held internally by the PLC,
and function to measure time. Timers
have coils and contacts. When a
preset time is reached, a contact
closes.
Timers : T 0~
Counters are held internally by the
PLC and count numbers. When a
preset number is reached, a contact
closes.
Counters : C 0~
Auxiliary relays are held internally by
the PLC and are also called "internal
relays."
The number of inputs relays, output relays, timers, counters, and other devices
varies according to the model of PLC.
Auxiliary relays : M 0~
ReferenceReferenceReference
Decimal, Octal and Hexadecimal
As shown in the following table, octal and hexadecimal numbers are assigned as
devices numbers in addition to decimal numbers.
Auxiliary timers, timers, countersInput relays, output relays
General-purpose Q/A Series
Micro PLC FX Series Octal Decimal
Hexadecimal Decimal
"Decimal"
"Octal"
"Hexadecimal"
The decimal number system is used most often, and counts up numbers in
units of ten in the format 0 to 9, 10 to 19, 20 to 29 and so forth.
The octal number system counts up numbers in units of eight in the format
0 to 7, 10 to 17, 20 to 27 and so forth.
The hexadecimal number system counts up numbers in units of 16 in the
format 0 to 9, 0A, 0B, 0C, 0D, 0E, 0F, 10 to 19, 1A, 1B, 1C, 1D, 1E, 1F and
so forth.

22
Expressions used in sequence diagrams and sequence programs
The sequence program on a PLC replaces the input device and output device connected
to each of the external terminals with a circuit for performing sequence control. For details
on instruction words, see Chapter 3.
The following explains how to replace a sequence diagram with a sequence program.
This example shows the tank water level control described on page 1-12 replaced with a
sequence program.
The following describes the various differences when a relay sequence program
is replaced with a sequence program.
SW
LS2 LS1
MC
MC
MC
MC
X000 X002 X001
Y000
Y000
SW LS2 LS1
Sequence diagram Sequence program
(1) How N.O. contacts and N.C. contacts are expressed
Relay sequence diagram Sequence program
N.O. contact
(2) The power supply circuit is not expressed.
(3) The sequence program is assigned devices numbers explained in the previous
page.
(4) Limit switch 2 in the sequence diagram is a N.C. contact but becomes a N.O.
contact in a sequence program.
This is because the role of limit switch 2 in the above sequence diagram is to
break the self-hold circuit of the MC and stop the MC. So, we should consider
that it is in a conducting state at all times on the circuit.
Next, remember the operation of the input relay on page 2-4. In operation of
the N.O. contacts and N.C. contacts in the sequence program, N.O. contacts
turn ON and N.C. contacts turn OFF when the input relay is electrically
conducting due to a change in state of the contact on the external wiring. Due
to this fact, a N.O. contact must be used on the sequence program to obtain
the same operating state.
In this way, when a PLC is used, N.O. contacts and N.C. contacts can be
used for each of the contacts on the sequence program.
Important
N.O. contact
N.C. contact N.C. contact

23
2.3 Wiring and Programs
What are PLC wiring and programs like?
The figure below shows the circuit on page 1-13.
I/O wiring must be handled in the
conventional way using cutting pliers
and a screwdriver.
The connections between input terminals and input relay coils and between
output contacts of output relays and output terminals were already established at
the delivery from the factory.
Complicated internal wiring in a PLC
(sequence program), can be handled
easily by operating the pushbuttons
(keys) on the programming panel.
SW
COM
X000
COM
Fuse
Y000 MC
X000 X002 X001
Y000
Y000
X001
X002
LS1
LS2
Output wiringSequence programIntput wiring
ThewiringofaPLCwiringcanbedividedupintoI/Owiringandinternalwiring.

24
2.4 Advantages of Using PLCs
Effective use of PLCs
1 Economical
In general, PLC is more inexpensive than conventional control box
where 10 or more relays are required.
2 Less manpower for design
Large amount of labor-saving can be achieved through simplified parts
layout drawings, sequence design and pre-start-up and test procedures.
3 Short turn-around time
The turn-around time can be significantly reduced through reduction in quantity
of procured parts, parallel procurement of the machinery and control box,
flexibility in specification change, simplified wiring work and so forth.
4 Downsizing and standardization
Significantly reduced in size than relay boards and mass-production is
possible by reusing the program.
6 Improved maintainability
Maintenance can be done in an easy manner, since few parts with life
limitation are used and the PLC has a self diagnosis function.
5 Improved reliability
Troubles due to relays and timers can be reduced and the component
with PLC can be used without any concern once the initial set-up of the
PLC is completed.
MITSUBISHI

25
Comparison with relay control
A Short History of PLCs
The device "PLC" came into being in 1968 as a result of
commissioned development by General Motors in the United States,
and the general market for PLCs started in the United States in the
following year. The first domestically produced PLC made its
appearance in Japan in 1970, yet it took six years for the first general-
purpose PLC to appear in 1976. MITSUBISHI ELECTRIC
CORPORATION initiated the market for general-purpose PLCs in the
year 1977, and has since made one-board PLC modules a familiar
name on the market. Since then, it has developed the general-purpose
PLC K series with integrated numeric value processing functions,
which was followed by the micro PLC F series with built-in
programmer. Today a variety of PLC products are available world wide
that can suite an array of control applications.
1
2
3
4
5
6
7
8
9
PLC controlMethodItem Relay control
Functionality
Reliability
Versatility
Device expandability
Ease of maintenance
Range of functions
Device size
Design, production period
PLCs can be used for any kind of
control depending on the program.
Once made, devices cannot
be used for other applications.
Changeability of control
content
PLCs can be repaired merely
by replacing modules.
PLCs can be freely expanded
up to their full potential.
If additions and modifications
are required they are difficult.
Analog and positioning control
also can be performed in
addition to sequence programs.
PLCs do not increase in size
even in complex, advanced
control applications.
Design is simple even for
complex control, and it does not
take time to manufacture PLCs.
Many drawings are required,
and it takes time to arrange
parts and test assemblies.
Relay control only is
supported.
Complex control is possible
by using many relays.
Control can be programmed
however complex it is.
Only the program needs to
be changed, and control can
be freely changed.
No other option but to
change the wiring
Reliability is higher as the
center of operations is made
up entirely of semiconductors.
Though there is no problem in regular
use, there are restrictions in faulty
contacts and service life of parts.
Periodic inspection and
limited service life parts must
be replaced.
Generally, large

27
SEQUENCE INSTRUCTIONS
What you have learned up till now
So far we have explained that PLCs are a collection of many relays, timers and
counters, and that their internal sequences can be wired by key operation on a
programming panel. When performing this wiring work, rules matched to contact
and coil connection methods and types of coils are required. These rules are the
instructions.
Instructions are programmed in the format "instruction word + devices number"
or by individual instruction words.
This chapter introduces several of the basic instructions for programming a PLC.
SEQUENCE INSTRUCTIONS
Chapter 3

3.1 Let's Remember PLC Instructions
There are two types of peripheral devices (programming devices) for entering
Sequence programs: devices for drawing sequence circuits on screen and
devices for entering programs using instruction words (that is, devices for
creating a list program). These devices differ only by program input method,
and the program itself is the same.
The following table summarizes the instructions held by a PLC, the meanings of
each instruction and how the circuit is indicated in a sequence program.
and used in circuit
indications indicate contacts.
Contacts are in two states,
conducting and non-
conducting, depending on
the ON/OFF state of input
relays or output relays,
auxiliary relays, timers, and
counters.
and SET show
driving of coils.
Devices used for input
using instruction words
Device used for input
using circuit diagrams
LD
LDI
AND
ANI
OR
ORI
ANB
ORB
OUT
SET
RST
NOP
END
Load
Load inverse
AND
AND inverse
OR
OR inverse
AND block
OR block
Out
Set
Reset
No operation
END
Bus connection
instruction,
N.O. contact
Bus connection
instruction,
N.C. contact
Series connection,
N.O. contact
Series connection,
N.C. contact
Parallel connection,
N.O. contact
Parallel connection,
N.C. contact
Series connection
between blocks
Parallel connection
between blocks
Coil drive
instruction
Retain operation,
coil instruction
Cancel retain
operation, coil
instruction
No operation
End of program End of program Return to 0 step
For deleting program or space
Symbol, Name Function Circuit Indication
28

29
Commands and Programs
Mechanism of Programs
The internal sequence for the sequence controlling is created as the sequence program with the format
of circuit diagram (ladder diagram) and instruction list.
A program is comprised of multiple instruction codes and device numbers (operand).
These instructions are numbered in turn. This number is referred to as step number. (Step numbers are
automatically controlled.)
Each "instruction" is comprised of "instruction code + device number". However, there are some
instructions without devices. Also in some cases, instruction codes are just referred to as instructions.
The max steps that can be programmed depend on the "program memory capacity" of the PLC that is used.
For example, there is a program memory with the capacity of "2000" steps in FX1S PLC, "8000" steps in
FX1N and FX2N, and "64000" steps in FX3U.
PLC repeatedly performs the instruction from step 0 to the END instruction. This operation is referred to as
cyclic operation, and the time required to perform this one cycle is referred to as operation cycle (scan
time).
Operation cycle will be changed according to the contents of the programs and the actual operating orders,
rom several msec o several tens of msec.
The PLC program created by the format of diagram (ladder diagram) is also stored in the program
memory of the PLC with the format of instruction list (program list).
The conversion between instruction list (program list) and diagram (ladder diagram) can be done by
using the programming software in personal computer.
X001
Y000
Y000
X003
0
4
END
X006
T1
K30
9
Circuit diagram (ladder diagram)
Step
number
Instruction
Instruction
code
Device (number)
(operand)
0
1
2
3
4
5
6
9
LD
OR
ANI
OUT
LD
ANI
OUT
END
X001
Y000
X003
Y000
Y000
X006
T1 K30
Instruction list (program list)
Repeatoperation
tranging
circuit
circuit

Preparing for programming
1. Open the connector cover on the top of
the PLC.
2. Connect one end of the FX-20P-CAB0
cable to the HPP connector on the PLC,
and the other end to the cable connector
on the FX-10P.
3. Set the PLC's RUN (operation) input to
the stop side.
4. Turn the PLC ON. As the HPP
(programming device) does not have its
own power supply, power is supplied to
the HPP via the program cable.
5. Program by the following procedure.
FX1S PLC
Insert in direction
marked by triangle
mark.
HPP main unit
Connector for
HPP connection
Repeatedly press
this cursor key.
Connector cover
RUN/STOP switch
Triangle mark
FX-20P-CAB0 type
program cable
Program all clear
HPP Operations
These function selection keys are switched
alternately and preference is given to the
last press of the key. For example, when
the key is first pressed, the
mode is the Read mode. When it is
pressed twice, the mode is the Write mode.
When it is pressed three times, the mode is
the Read mode.
The top row on these keys indicates an
instruction word, while the symbol on the
bottom row indicates a devices symbol or
number. The HPP automatically judges
operation of these keys according to the
operation procedure. To correct a
misoperation, press the key.
Clear
Read/Write
Read
/
Write
Insert
/
Delete
Monitor
/
Test
Clear
30

OUT
END
List programCircuit program
Output Y000 turns ON when input X000 is ON.
Output Y003 turns ON when input X003 is OFF.
OFF
ON
ON
ON
The LD (Load) instruction is used
for the first N.O. contact used on
the bus, and the LDI (Load
inverse) instruction is used for
N.C. contacts. Contact
instructions such as LD and LDI
are used for devices such as
input relays X, output relays Y,
timers T, counters C, and
auxiliary relays M.
Coil drive instructions such as
OUT are used for devices other
than input relays X.
OFF
OFF
ON
OFFInput X 000
By the above program...
Output Y 000
Output Y 003
OFF
(Note 1)
(Note 2)
0 LD X 000
OUT Y 000
LDI X 000
OUT Y 003
END
1
2
3
4
Step Instruction
0
X 000
OUT(Note 2)LD(Note 1)
LDI(Note 1)
This is called a "bus".
X 000
2
4
Y 000
Y 003
END
LD
LDI
Bus connection
instruction for N.O.
contacts
Load
Bus connection
instruction for N.C.
contacts
Load inverse
Coil drive instruction
Out
Instruction used for
the end of a program
End
Step numbers
Step numbers indicate the order and
size of a program.
If you program instructions in the
order of the list program, the PLC will
automatically assign the step
numbers.
31

32
SET
RST
Circuit program
Output Y000 turns ON when input X001 is turned
ON.
After this, the operation state of Y000 is held at
ON even if the state of input X001 changes from
ON to OFF.
Output Y000 turns OFF when input X003 is
turned ON.
ON
ON
These instructions drive
coils like the OUT
instruction.
With the OUT instruction,
coils programmed with
the OUT instruction also
turn OFF when the
contact that drives the
coil changes state from
ON to OFF. However,
when the SET (Set)
instruction is used, the
operation state of the coil
is held at ON even if the
state of the contact
changes from ON to
OFF.
The RST (Reset)
instruction is used to
change the state of the
coil driven by the SET
(Set) instruction from ON
to OFF.
ON
Input X 001
Input X 003
Output Y 000
List program
0 LD X 001
SET Y 000
LD X 003
RST Y 000
END
1
2
3
4
Step Instruction
The SET/RST instructions are
used for output relays Y and
auxiliary relays M, for example.
The RST instruction is also used
for counters and retentive timers.
0
X 001
X 003
2
4 END
RST
SET Y 000
Y 000
Operation hold
output instruction
Set
Operation hold
cancel instruction
Reset

33
Output Y000 turns ON when input X000 is ON,
X001 is ON and X002 is OFF.
Output Y003 turns ON when input X000 is ON,
X001 is ON, X002 is OFF, and X003.
OFF
ON
ON
The AND (AND) instruction is
used for N.O. contacts and the
ANI (AND Inverse) instruction
is used for N.C. contacts
connected serially following
the LD and LDI instructions.
Y000 and Y003 operate when
all contacts serially connected
that are driving AND and ANI
are conducting.
The contact instruction
for this position is AND or
ANI.
ON
Input X 000
Input X 002
ONInput X 001
ONInput X 003
ONOutput Y 000
ONOutput Y 003
0 LD X 000
AND X 001
ANI X 002
OUT Y 000
X 003AND
Y 003OUT
END
1
2
3
4
5
6
Step Instruction
0
X 001
AND ANI
X 002X 000
AND(Note 1)
X 003
6
Y 000
Y 003
END
AND
ANI
Series connection
contacts
AND
Series connection
contacts
AND inverse
(Note 1)

34
OR
ORI
Output Y000 turns ON when even one condition,
input X000 ON, X001 ON or X002 OFF, is
satisfied.
OFF
ON
ON
The OR (OR) instruction is
used for N.O. contacts and the
ORI (OR Inverse) instruction is
used for N.C. contacts
connected in parallel following
the LD and LDI instructions.
Output Y000 in the figure on
the left operates when even
one of the contacts connected
in parallel that is driving OR
and ORI is conducting.
ON
Input X 000
Input X 002
ONInput X 001
ONOutput Y 000
0 LD X 000
OR X 001
ORI X 002
OUT Y 000
END
1
2
3
4
Step Instruction
0
X 001
X 002
X 000
4
Y 000
END
Parallel connection
contacts
OR
Parallel connection
contacts
OR inverse

35
ANB
Y000 operates when either of input X000 or X001
and either of X002 or X003 are ON
simultaneously.
ON
The ANB (AND block)
instruction is used to serially
connect a circuit to which
contacts are connected in
parallel as shown in the figure
on the left. A devices number
is not assigned to the ANB
instruction. In programs like
this, the contact for input X002
also becomes an LD
instruction.
X001 and X003 become OR
instructions as these are
contacts connected in parallel
to X000 and X002 that are LD
contacts.
ON
Input X 000
Input X 002
ONInput X 001
ONInput X 003
ONONOutput Y 000
0 LD X 000
OR X 001
LD X 002
OR X 003
ANB
Y 000OUT
END
1
2
3
4
5
6
Step Instruction
0
ANB
X 002
LD instruction also from
beginning of branch
Parallel circuit block
OR instruction before
ANB instruction
X 000
X 003X 001
Y 000
END
Series connection
instruction for
parallel circuit block
AND block

36
ORB
Output Y000 operates when either inputs X000
and X001 are simultaneously ON or when inputs
X002 and X004 are simultaneously ON.
ON
The OR and ORI instructions
connect a single contact in
parallel to the previous LD
contact. However, as shown in
the figure on the left, the ORB
(OR block) instruction is used
to connect a circuit, to which
contacts are connected in
series, in parallel.
A devices number is not
assigned to the ORB
instruction.
In programs like this, the
contact for input X002 also
becomes an LD instruction.ON
Input X 000
Input X 002
ONInput X 001
ONInput X 003
ONONOutput Y 000
0 LD X 000
AND X 001
LD X 002
AND X 003
ORB
Y 000OUT
END
1
2
3
4
5
6
Step Instruction
0
ORB
Series circuit block
Y 000
END
Parallel connection
instruction for series
circuit block
OR block
X 001X 000
X 003X 002

37
NOP No operation
instruction
When an all clear has been performed on a program, all instructions become
NOP.
The PLC ignores NOP instructions inserted between general instructions.
However, be sure to delete NOP instructions as much as possible as they use up
unnecessary program steps and make it longer to calculation programs.
No operation
Time for a break!

38
A program like the one above is made using 16 program steps, (1) to (16).
The following shows the above program rewritten as a list program.
3.2 Order of Programs
Program order
Circuit diagrams are programmed from left to right and from top to bottom.
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
LD
OUT
LD
OR
AND
OUT
OUT
LD
AND
LD
AND
ORB
OUT
OUT
OUT
END
X 000
Y 000
X 001
X 002
X 003
Y 001
Y 002
X 004
X 005
X 006
X 007
Y 003
Y 004
Y 005
Step Instruction
Y 000
Y 001
Y 002
Y 003
Y 004
Y 005
END
X 000
(1)
X 001
(3)
X 003
(5)
X 002
(4)
X 004
(8)
X 005
(9)
X 006
(10)
X 007
(11) (12)
(2)
(6)
(7)
(13)
(14)
(15)
(16)

39
3.3 About Timer Circuits
0
1
2
5
6
7
Timers
Reference
Timer program
Of the various timers available, this section
describes how to program a digital timer that
is held internally on a micro PLC.
LD
OUT
OUT
SP
LD
OUT
END
X 000
Y 000
T0
K 100
T0
Y 003
Timer program
Enter set value
X 000
K 100
(10 secs)
T 0
0
5
7
Y 000
T0
END
Y 003
The timer contact operates after a
preset delay has elapsed after the
coil has been made conductive.
(ON delay timer)
This preset time is called the "set
value" and is expressed as K
which can be set in the range 1 to
32,767.
For example, K100 is a timer of
ten seconds.
When X000 is turned OFF while
the timer is being driven, the
present value of the timer returns
to "0" and the timer contact also
turns OFF.
Key operation
Monitor
mode
M
Let's try using monitor functions.
Monitor
/
Test
When the monitor mode is selected, "M" is
displayed at the top left of the FX-10P screen.
ON
ON
Input X000
Output T0 (N.O. contact)
ONOutput Y000, T0 (coil)
ONOutput Y003 (coil)
10 secs
Step Instruction
input from
Personal
Computer
OUT T0 K100,

40
3.4 About Counter Circuits
Counters
Counter program
Of the various counters available, this section
describes how to program a general-purpose
counter that is held internally on a micro PLC.
0
1
3
4
7
8
LD
RST
LD
OUT
SP
LD
OUT
9 END
X 001
C0
C0
X 003
K 10
C0
Y 003
Counter program
Enter set value.
Counters count the number of
times a contact (X003) changes
state from OFF to ON.
This contact (X003) is called the
"count input," and the value
counted by the counter is called
the "present value."
The counter operates when the
present value reaches the
specified number (set value).
The set value can be set a value
within the range 1 to 32,767.
After the counter has counted up,
the present value of the counter
does not change, and the output
contact stays in an operating
state.
When reset input X001 turns ON,
the present value of the counter
returns to "0" and the counter
contact also turns OFF.
Key operation
Monitor
mode
Operation
Output Y003
Present value of
counter C0
Input X003 (count)
(reset)
0
1
2
3
4
5
6
7
8
9
10
Step Instruction
Monitor
/
Test
ON
Input X001
( t)
0
3
7
9
X 001
X 003
Reset input
Count input
C 0
C0
RST C0
Y 003
K10
END
Reference
Let's try using monitor
functions.
For example,
a pedometer
input from
Personal
Computer
OUT T0 K10,

41
3.5 About Self-hold Circuits
Output operation can be held or cancelled by
programming a self-hold sequence.
0
1
2
3
4
LD
OR
ANI
OUT
END
X 003
Y 003
X 004
Y 003
Y003 turns ON when X003 is
ON and X004 is OFF.
Y003 continues to operate
even if X003 is turned OFF.
(This is "self-hold operation.")
Y003 turns OFF when X004 is
turned ON.
Circuit program List program
ON
ON
Input X003
Output Y003
ONInput X004
X 003
Y 003
X 004
0 Y 003
Both of the following are the same self-hold circuit.
Step Instruction

42
Starting with simple programs
Enough for theory, and now for practice
In this chapter, you study all about handling and operation such as programming
and monitoring based on some simple examples.
PROGRAM TRAINING
Chapter 4

Escalator
drive Y003
Pass detection switch: 1
X003
Illumination
lamp Y000
Passdetection switch: 0
X001
So,thism
atacts
like
a
switch,
right?
43
4.1 Introductory Example 1 (Control of
Escalators)
I/O assignments
Input Pass detection switch:0 X001
Pass detection switch: 1 X003
Output Illumination lamp Y000
Escalator drive output Y003
Operation
(1)Let's assume that the escalator does not move until someone approaches it.
(2)When someone approaches the escalator and turns on pass detection switch:
0, the illumination lamp lights and the escalator starts to move. (Escalator
movement is up only.)
(3) The person is carried up by the escalator, and when that person moves off
the escalator, pass detection switch: 1 turns ON, and the illumination lamp
and escalator return to a non-operating state.
In this example, consider both pass detection switches: 0 and 1 as non-hold type
switches.
Another assumption in this example is that people do not continue to get on this
escalator.
Let's consider a PLC program for an escalator.

44
The program is configured as follows
Circuit program
List program Let's check operation
Enter the above program on the PLC, and
check program operation.
When input X001 is turned ON, outputs Y000
and Y003 operate. Next, when input X003 is
turned ON, outputs Y000 and Y003 become
non-operational.
Key operation
After preparing for programming (see page 3-3), create the program using the
following key operations.
w 0 N O P
1 N O P
w 1 O R Y 0 0 0
1 N O P
w 5 E N D
6 N O P
Pass detection
switch: 0
X001
Pass detection
switch: 1
X003
Illumination lamp ON
Escalator drive
Self hold
Y000
PLC power
ON
Online
selection
Y000
Y003
END
Writing the program
Read
Write
Write All clear operation
Step Instruction
0
1
2
3
4
5
LD X001
OR Y000
ANI X003
OUT Y000
OUT Y003
END

45
4.2 Introductory Example 2 (Control of Tea Dispenser)
Let's consider a PLC program for a tea dispenser
I/O assignments
Input Cup detection X000 (ON when cup is present)
Dispense tea button X001
Check tea leaves button X002
Replenish water tank lower limit switch X003
Replenish water tank upper limit switch X004
output Change tea leaves indicator lamp Y000
Dispense tea output Y001
Replenish water output Y003
Explanation of operation
(1)When cup detection X000 is ON, and dispense tea button X001 is pressed
(X001 turns ON), dispense tea output Y001 operates, and hot water is poured
into the cup. Hot water is poured only for the duration that the button is
pressed, and stops being poured when you release your hand from the
button.
When cup detection X000 is OFF, hot water is not poured even by pressing
dispense tea button X001.
(2)When water in the replenish water tank gets low, lower limit switch X003 turns
ON and replenish water output Y003 operates.
When replenish water output Y003 operates and water is poured into the tank,
upper limit switch X004 finally turns ON, and replenish water output Y003
becomes non-operational.
(3)When water is replenished five times, the change tea leaves indicator lamp
lights.
(4)When the check button is pressed, the change tea leaves indicator lamp goes
out.
Change tea leaves
Replenish water output
Upper limit switch
Lower limit switch
Cup detection
Dispenseteaoutput
Dispense tea button
Y 003
Y 000
Dispense Check
Check tea
leaves
X 002
X 003
X 000
X 004
X 001
Y 001

46
Circuit program
Enter the above program on the PLC, and
check program operation.
(1)Output Y001 operates when both inputs
X000 or X001 turns ON.
(2)When input X003 turns ON, output Y003
operates, and when input X004 turns ON,
output Y003 becomes non-operational.
(3)Each time that output Y003 operates, the
value of counter C0 is incremented by one.
When C0 reaches "5", Y000 operates.
(4)When input X002 turns ON, the value of
counter C0 returns to "0" and output Y000
becomes non-operational.
(Remarks)
With the FX-I/O demonstration training machine,
the volume of the output Y001 buzzer can be
adjusted. To raise the volume, turn the variable
resistor on the top of the buzzer clockwise. To
lower the volume, turn it counterclockwise.
List program
Step Instruction
0
1
2
3
4
5
6
7
11
12
13
14
16
LD X000
AND X001
OUT Y001
LD X003
OR Y003
ANI X004
OUT Y003
LD Y003
LD C0
OUT Y000
LD X002
RST C0
END
X 000 X 001
X 003 X 004
Y 003
X 002
Y 000
RST C0
C0
Y 001
END
C 0
Y 003
K 5
Y 003
Self hold
Lower limit switch Upper limit switch
Dispense tea button
Dispense tea output
Replenish water count
Change tea leaves indicator lamp
Counter reset
Cup detection
Check button
input from
Personal
Computer
OUT C0 K5,
OUT C0
SP K5
8

47
4.3 Introductory Example 3 (Control of Drilling Machine)
Let's consider a PLC program for drilling on a drilling machine.
I/O assignments
Input Stop button X000
Operation start button X001
Fall start button X002 (Consider this to be an auto-return type pushbutton.)
Fall end limit switch X003
Rise end limit switch X004
output Drill rise output Y000
Drill fall output Y001
Drill rotation output Y003
When operation start button X001 is pressed, drill rotation output Y003 operates
and the drill starts to rotate.
When stop button X000 is pressed, drill rotation output Y003 becomes non-
operational, and drill operation stops.
If fall start button X002 is pressed during drill rotation, drill fall output Y001
operates, and the drill starts to fall. When the drill finally reaches the position of
the fall end limit switch, fall end limit switch X003 turns ON, and the drill fall
operation stops.
Three seconds after the drill fall operation stops, drill rise output Y000 operates,
and the drill rises.
The drill rise operation ends when rise end limit switch X004 turns ON after drill
rise operation has begun.
Upper end limit switch
X 004
Y 000
Y 001
Y 003
X 003
X 002
X 000
X 001
Drill rise output
Drill fall output
Lower end limit switch
Fall start
button
Stop
button
Operation start
button
DOWN
STOP
RUN
Drill rotation output

48
Circuit program
X 001 X 000
X 003
X 003
Y 001X 004
X 002
Y 003
Y 000
T0
Y 003
END
T 0
Y 003
Y 001
Y 000
K 30
Y 001
Self hold
Self hold
Fall start button Drill rotation
in progress
Fall end
limit switch
Interlock
Stop button
Self hold
Drill rotation
Drill fall
Drill rise
Operation start button
Fall end limit switch
Rise end
limit switch
Interlock
Y 000
List program
Step Instruction
0
1
2
3
4
5
6
7
8
9
10
14
15
16
17
18
19
LD X001
OR X003
ANI X000
OUT Y003
LD Y002
OR Y001
AND Y003
ANI X003
ANI Y000
OUT Y001
LD X003
LD T0
OR Y000
ANI X004
ANI Y001
OUT Y000
END
input from
Personal
Computer
OUT T0 K30,
Enter the above program on the PLC,
and check program operation.
(1)When input X001 is turned ON, output
Y003 operates. When input X000
turns ON, output Y003 becomes non-
operational.
(2)If input X002 is turned ON while
output Y003 is operating, output Y001
operates. When input X003 is turned
ON, output Y001 becomes non-
operational.
(3)If input X003 is held in an ON state,
timer T0 starts to count. After three
seconds, the T0 contact turns ON.
(4)When timer T0 turns ON, output Y000
operates. When input X004 turns ON,
output Y000 becomes non-
operational.
OUT T0
SP K30
11

49
4.4 Introductory Example 4 (Control of Quiz Answer Display Panel)
Let's try considering a sequence program for a quiz program.
I/O assignments
Input Children's buttons X000 X001 output Children's lamp Y000
Adult's buttons X002 X003 Adult's lamp Y001
MC's button X004 Jackpot ball open buttonY004
Lucky chance switch X005
(1) Light the lamp that is the quickest to respond to the MC's question.
(2) The lamp lights until the MC presses pushbutton X004. Note, that the
children's team has an advantage as lamp Y000 can be made to light
whichever of pushbuttons X000 and X001 is pressed.
The adults' team have a disadvantage as lamp Y001 does not light unless
both pushbuttons X002 and X003 are pressed.
(3) When the MC has turned lucky chance switch X005 ON, the children have a
lucky chance to open the jackpot ball if they press the button within ten
seconds.
Jackpot ball
Pushbutton
switch
MC
Pushbutton
switch
Lamp
Lamp
Children
Lucky chance
switch
Adults
X 000 X 001 X 002 X 003
Y 000
Y 001
X 005
X 004
SW
PB4
SOL Y 004

50
Circuit program
Enter the above program on the PLC,
and check program operation.
(1)When X000 or X001 turns ON,
output Y000 operates and holds its
own state. Note, however, that
Y000 does not turn ON if Y001
turned ON first.
(2)Operation of Y001 is the same
except that when X004 turns
OFF, the self hold is canceled
(reset).
(3)When lucky chance input X005
turns ON, jackpot ball open output
Y005 also holds its own state by
Y000 turning ON.
Note, however, that this operation
is not performed when T0 is
OFF. When X005 turns ON, timer
T0 starts to operate, and the output
contact operates ten seconds later.
X 000
X 001
X 004
X 004
Y 000 X 005
X 005
X 002
Y 000
Y 001
Y 004
T 0
X 003
Y 001
Y 000
Adults
Children
Lucky chance
MC Children
MC Adults
Children
Children
Children
Adults Adults
Children's lamp
Adults' lamp
Open jackpot ball
Lucky chance
END
K 100
Y 001
T0
Y 000
Y 004
Step Instruction
0
1
2
3
4
5
6
7
8
9
Step Instruction
10
11
12
13
14
15
16
17
18
19
20
List program
Let's try considering the program.

51
Let'suseapersonalcomputertocreatetheprograms!
Appendix 1
THE OPERATION OF THE GX Developer
Using a personal computer, sequence becomes easier
If a personal computer software GX Developer is used to create and edit the sequence
program, it becomes easier just like illustration making.
If the basic operations are mastered, it is just the repetition of them.
There are many functions easy to use in the software. Let’s master them sequentially
starting from the necessary operations.
Smoothly starting up and adjusting
The program is accompanied by the debug.
The operation status of the PLC and program can be monitored on the personal
computer screen, so if some parts are not working as planned, conﬁrmation and
adjustment can be conducted at once.
Make the program easy to read
There is a "comment input function" in GX Developer to make the sequence program
easy to read.
It can improve the efﬁciency to create and debug the program if a comment is input.

52
Appendix 1.1 Basic knowledge for operating GX Developer
Appendix 1.1.1 Construction of the GX Developer’s screen
Title bar
The name of the opened project and the operation icon of windows are displayed.
1)
1) Title bar
6) Status bar
2) Menu bar
3) Tool bar
5) Edit screen
4) Project data list
Changing the size of GX Developer and quitting it Maximizing and restoring down GX Developer
Quitting GX DeveloperMinimizing GX DeveloperDisplay of the project
name and its path
1) Title bar
6) Status bar
2) Menu bar
3) Tool bar
5) Edit screen
4) Project data list

53
Menu bar2)
Drop down menu will be displayed after menu is selected.
Tool bar3)
*: The contents of the tool bar can be moved, added and removed, therefore the displayed items and
the layouts depend on the various environments.
Project data list4)
Circuit creating window, parameter setting screen and so on are displayed by tree structure.
The description
of the function
will be displayed
when the mouse
cursor stops at
the buttons.
Directly specify the items
displayed by mouse clicking.
The frequently used functions are conﬁgured by icon buttons. Compared to selecting from the menu,
the desired function can be directly executed.

54
Edit screen5)
Status bar
The status of the operation and setting is displayed.
6)
5) Edit screen
Scroll Lock status
The instruction of the
mouse cursor position
CPU
type
The location of the
CPU connected
Caps Lock
status
Num Lock
status
Current input mode is displayed
Circuit creating screen, monitor screen and so on are multiply displayed by windows.

55
Appendix 1.1.2 About the "Project"
"Project" consists of Program, Comment, Parameter and Device Memory.
An aggregate of a series of data in GX Developer is called "Project", and stored as a folded of
Windows®
.
Editing multiple projects
Start multiple GX Developer when more than one projects are to be edited.
●
Project
Program
Comment
Parameter
Device Memory
This is equivalent to the of Windows®
.
Sequence program
Comment on the devices
Parameter setting data of PLC
Contents of the current device value, or the input device value
folder

56
Appendix 1.2 Starting GX Developer and creating a new project
Appendix 1.2.1 Starting GX Developer
Start from the Start button of Windows, and
select in the following order.
[Programs]
↓
[MELSOFT Application]
↓
[GX Developer]
1)
GX Developer is started.2)

57
Select from the tool bar, or select [Project]
→ [New project] ( Ctrl + N ) from the menu.
Click the [▼] button of [PLC series].
1)
2)
Appendix 1.2.2 Creating a new project
Select "FXCPU".
Click the [▼] button of [PLC type].
3)
4)
Select "FX3U(C)".
Note: Select the series name that is actually
used.
5)
1) Click
1) Click
3) Click and select
2) Click
5) Click and select
4) Click

58
Click OK .6)
New project screen is displayed and the
project can be input.
7)
About the parameter setting
In FX PLC, it is not necessary to set the parameters when the comments stored in PLC are not
set or ﬁle registers are not used.
For the details of the parameters, see Appendix.
●
Point
6) Click
7) New project screen

59
Appendix 1.3 Creating a circuit
Appendix 1.3.1 Creating a circuit by using the function keys
[The circuit to be created]
X002
Y000
Y000
X000
X003
Y001
The relationship between the function keys and the symbols of the circuit is displayed on the
buttons of the tool bar.
Main key operations
When creating a circuit, make sure to set to "Write Mode".
Select from the tool bar. Select from the menu ([Edit] → [Write mode]).
Use half-width characters when inputting. Full-width characters are not allowed.
●
●
●
Point
F5 F6 F7
F8
F9
F5
Shift Shift
F6
Shift
F9
Ctrl
F10
F9
Ctrl
＋＋＋＋
＋
In this book, the number of the input
relay and output relay is displayed
as "X000", "Y000" by three digits.
"X0", "Y1" and the "0" on the left
front can be omitted when the input
is performed from GX Developer.
Point

60
Press the F5 key.
Input "X2".
1)
The circuit input
X0
is displayed.
Press the F7 key.
Input "Y0".
Conﬁrm it by the Enter key or [OK].
6)
7)
8)
The circuit input is displayed.
Press the Shift + F5 key.
Input "Y0".
9)
10)
11)
The circuit input
X2
is displayed.
Press the F6 key.
Input "X0".
3)
4)
5)
Cancel it by ESC or
[Cancel].
Conﬁrm it by the Enter key or [OK].2)
1) Input "X2" 2) Input the Enter key
4) Input "X0"
3) The circuit is displayed
5) Input the Enter key
7) Input "Y0" 8) Input the Enter key
11) Input the Enter key10) Input "Y0"

61
The circuit input
Y0
is displayed.
Move the cursor to the beginning of the next
line.
Press the F5 key.
Input "X3".
12)
13)
14)
15)
The circuit input
X3
is displayed.
Press the F7 key.
Input "Y1".
16)
17)
18)
!!The circuit is created!!
19)
13) Move the cursor
15) Input the Enter key14) Input "X3"
17) Input "Y1"
18) Input the Enter key
F4 (Convert)
20) The grey display disappears
Circuit-Conversion Operation [Important]
Do the "Conversion" operation to confirm the
circuit diagram that is not confirmed (the grey
displayed part).
Press the F4 (Convert) key.
Or select from the tool bar, or select
[Convert] → [Convert] from the menu.
20)
The grey display disappears and the circuit is
confirmed.
If an error occurs, the cursor moves to the failure
part of the created circuit. Correct the circuit.

62
Appendix 1.3.2 Creating a circuit by using the tool buttons
[The circuit to be created]
Click the tool buttons to input the symbols of the circuit.
Main tool buttons
When creating a circuit, make sure to set to "Write Mode".
Select from the tool bar. Select from the menu ([Edit] → [Write mode]).
●
●
●
Point
X002
Y000
Y000
X000
X003
Y001
In this book, the number of the input
relay and output relay is displayed
as "X000", "Y000" by three digits.
"X0", "Y1" and the "0" in the left front
can be omitted when the input is
performed from GX Developer.
Point

63
The circuit input
X0
is displayed.
Click the tool button .
Input "Y0".
6)
7)
8)
Input "Y0".
9)
10)
11)
Cancel it by ESC
or [Cancel].
The circuit input
X2
is displayed.
Press the tool button .
Input "X0".
3)
4)
5)
Conﬁrm it by the Enter key or [OK].2)
Input "X2".
1)
2) Click1) Input "X2"
8) Click7) Input “Y0”
11) Click10) Input “Y0”

64
The circuit input
Y0
is displayed.
Move the cursor to the beginning of the next
line.
Input "X3".
12)
13)
14)
15)
The circuit input
X3
is displayed.
Input "Y1".
16)
17)
18)
!!The circuit is created!!
19)
13) Move the cursor
18) Click17) Input "Y1"
F4 (Convert)
20) The grey display disappears
Circuit-Conversion Operation [Important]
Do the "Conversion" operation to confirm the
circuit diagram that is not confirmed (grey
display part).
Press the F4 (Convert) key.
Or select from the tool bar, or select
[Convert] → [Convert] from the menu.
20)
The grey display disappears and the circuit is
confirmed.
If an error occurs, the cursor moves to the failure
part of the created circuit. Correct the circuit.

65
Appendix 1.4 Writing programs to PLC
Write the created sequence program to FX PLC.
Appendix 1.4.1 Connecting PC to PLC
Example for connection (Personal computer side: RS-232C)1)
Example for connection (Personal computer side: USB)2)
Check the COM port number that the driver of FX-USB-AW assigns to the
personal computer. For the check procedures, see the manual of FX-USB-
AW.
●
FX3U-48MR/ES
FX3U-48MFX3U
ERROR
RUN
BATT
POWER
R
0 31 2
IN
OUT
64 5 217 20 2422 23 2625
10 11 1312 1614 15 17
27
0 31 2 64 5 217 20 2422 23 2625
10 11 1312 1614 15 17
27
Y12Y10 Y16Y14 Y22Y20 Y26 COM5
COM1
Y24Y6Y4Y2Y0
Y7 Y11 Y13Y5COM2Y3Y1 COM3 Y15 Y17COM4 Y23 Y25 Y27Y21
X5
X0
X1
X2
X3 X7 X11 X13
X40VS/S
N 24V
X6 X10 X12 X14 X16 X20
L X27X23 X25X15 X17 X21
X24 X26X22
FX3U-48MR/ES
FX3U-48MFX3U
ERROR
RUN
BATT
POWER
R
0 31 2
IN
OUT
64 5 217 20 2422 23 2625
10 11 1312 1614 15 17
27
0 31 2 64 5 217 20 2422 23 2625
10 11 1312 1614 15 17
27
Y12Y10 Y16Y14 Y22Y20 Y26 COM5
COM1
Y24Y6Y4Y2Y0
X5
X0
X1
X2
X3 X7 X11 X13
X40VS/S
N 24V
X6 X10 X12 X14 X16 X20
L X27X23 X25X15 X17 X21
X24 X26X22
PLC
built-in port
(RS-422)
FX-422CAB0
RS-232C
F2-232CAB-1
FX-232AWC-H
(RS-232C/RS-422 converter)
GX Developer
FX3U-48MR/ES
FX3U-48MFX3U
ERROR
RUN
BATT
POWER
R
0 31 2
IN
OUT
64 5 217 20 2422 23 2625
10 11 1312 1614 15 17
27
0 31 2 64 5 217 20 2422 23 2625
10 11 1312 1614 15 17
27
Y12Y10 Y16Y14 Y22Y20 Y26 COM5
COM1
Y24Y6Y4Y2Y0
X5
X0
X1
X2
X3 X7 X11 X13
X40VS/S
N 24V
X6 X10 X12 X14 X16 X20
L X27X23 X25X15 X17 X21
X24 X26X22
FX3U-48MR/ES
FX3U-48MFX3U
ERROR
RUN
BATT
POWER
R
0 31 2
IN
OUT
64 5 217 20 2422 23 2625
10 11 1312 1614 15 17
27
0 31 2 64 5 217 20 2422 23 2625
10 11 1312 1614 15 17
27
Y12Y10 Y16Y14 Y22Y20 Y26 COM5
COM1
Y24Y6Y4Y2Y0
X5
X0
X1
X2
X3 X7 X11 X13
X40VS/S
N 24V
X6 X10 X12 X14 X16 X20
L X27X23 X25X15 X17 X21
X24 X26X22
USB
FX-USB-AW
(USB/RS-422 converter)
GX Developer
PLC
built-in port
(RS-422)

66
Transparent function of GOT1000 (Personal computer side: USB)3)
FX3U-48MR/ES
FX3U-48MFX3U
ERROR
RUN
BATT
POWER
R
0 31 2
IN
OUT
64 5 217 20 2422 23 2625
10 11 1312 1614 15 17
27
0 31 2 64 5 217 20 2422 23 2625
10 11 1312 1614 15 17
27
Y12Y10 Y16Y14 Y22Y20 Y26 COM5
COM1
Y24Y6Y4Y2Y0
X5
X0
X1
X2
X3 X7 X11 X13
X40VS/S
N 24V
X6 X10 X12 X14 X16 X20
L X27X23 X25X15 X17 X21
X24 X26X22
FX3U-48MR/ES
FX3U-48MFX3U
ERROR
RUN
BATT
POWER
R
0 31 2
IN
OUT
64 5 217 20 2422 23 2625
10 11 1312 1614 15 17
27
0 31 2 64 5 217 20 2422 23 2625
10 11 1312 1614 15 17
27
Y12Y10 Y16Y14 Y22Y20 Y26 COM5
COM1
Y24Y6Y4Y2Y0
X5
X0
X1
X2
X3 X7 X11 X13
X40VS/S
N 24V
X6 X10 X12 X14 X16 X20
L X27X23 X25X15 X17 X21
X24 X26X22
RS-422
GOT1000
USB
USB
GT09-C30USB-5P
GX Developer
PLC
built-in port
(RS-422)

67
Appendix 1.4.2 "Transfer Setup" in GX Developer
Configure the settings of GX Developer to communicate with PLC.
Select [Online] → [Transfer Setup].
Double-click the icon .
1)
2)
Set the communication port of personal
computer side.
(a) Select "RS-232" when RS-232 connector is
used at personal computer side or FX-USB-AW
is used with the USB connector at personal
computer side.
(b) Select "USB (GOT transparent mode)" when
the transparent function of GT1000 is used with
the USB connector at personal computer side.
(c) · When RS-232C connector is used at personal
computer side, the port is usually COM1.
(It may change depending on personal
computers.)
· Specify the COM port number that the driver
assigns when using FX-USB-AW. (See
Section 3.7.1)
3)
Click [OK] after the setting is completed.
Click [Connection test], to check the
communication with PLC.
After checking, click [OK] to confirm the
setting configured.
4)
5)
6)
1) Transfer Setup is displayed
2) Double-click
3) (a)
3) (b)
3) (c)
4) Click
5) Click
6) Click

68
Appendix 1.4.3 Writing a program to the PLC
Set the "RUN/STOP" switch of PLC to
"STOP".
1)
[Online] → [Write to PLC] from the menu.
Click [Param + Prog].3)
Select from the tool bar or select2)
Click [Execute].4)
FX3U-48MR/ES
FX3U-48MFX3U
ERROR
RUN
BATT
POWER
R
0 31 2
IN
OUT
64 5 217 20 2422 23 2625
10 11 1312 1614 15 17
27
0 31 2 64 5 217 20 2422 23 2625
10 11 1312 1614 15 17
27
Y12Y10 Y16Y14 Y22Y20 Y26 COM5
COM1
Y24Y6Y4Y2Y0
X5
X0
X1
X2
X3 X7 X11 X13
X40VS/S
N 24V
X6 X10 X12 X14 X16 X20
L X27X23 X25X15 X17 X21
X24 X26X22
FX3U-48MR/ES
FX3U-48MFX3U
ERROR
RUN
BATT
POWER
R
0 31 2
IN
OUT
64 5 217 20 2422 23 2625
10 11 1312 1614 15 17
27
0 31 2 64 5 217 20 2422 23 2625
10 11 1312 1614 15 17
27
Y12Y10 Y16Y14 Y22Y20 Y26 COM5
COM1
Y24Y6Y4Y2Y0
X5
X0
X1
X2
X3 X7 X11 X13
X40VS/S
N 24V
X6 X10 X12 X14 X16 X20
L X27X23 X25X15 X17 X21
X24 X26X22
1) Set to "STOP"
2) Click
4) Click
3) Select the data
to be written
5) Click
The dialog box of the progressing rate is
displayed.

69
Appendix 1.4.4 Operation monitor of the program
Set the "RUN / STOP" switch of PLC to
"RUN".
1)
Operation check by operation monitor
Set [Switch X002 is "ON"] with the status [Switch X000 is "OFF"], and then check [Output Y000 is
"ON"].
Check [Output Y000 is "ON"] while [Switch X002 is "OFF"].
Set [Switch X000 is "ON"] and then check [Output Y000 is "OFF"].
Check [Output Y001 is "ON/OFF"] in accordance with [Switch X003 is "ON/OFF"].
1)
2)
3)
4)
FX3U-48MR/ES
FX3U-48MFX3U
ERROR
RUN
BATT
POWER
R
0 31 2
IN
OUT
64 5 217 20 2422 23 2625
10 11 1312 1614 15 17
27
0 31 2 64 5 217 20 2422 23 2625
10 11 1312 1614 15 17
27
Y12Y10 Y16Y14 Y22Y20 Y26 COM5
COM1
Y24Y6Y4Y2Y0
X5
X0
X1
X2
X3 X7 X11 X13
X40VS/S
N 24V
X6 X10 X12 X14 X16 X20
L X27X23 X25X15 X17 X21
X24 X26X22
FX3U-48MR/ES
FX3U-48MFX3U
ERROR
RUN
BATT
POWER
R
0 31 2
IN
OUT
64 5 217 20 2422 23 2625
10 11 1312 1614 15 17
27
0 31 2 64 5 217 20 2422 23 2625
10 11 1312 1614 15 17
27
Y12Y10 Y16Y14 Y22Y20 Y26 COM5
COM1
Y24Y6Y4Y2Y0
X5
X0
X1
X2
X3 X7 X11 X13
X40VS/S
N 24V
X6 X10 X12 X14 X16 X20
L X27X23 X25X15 X17 X21
X24 X26X22
1) Set to "RUN"
2) Click
Select from the tool bar or select [Online]
→ [Monitor] → [Monitor mode] from the menu.
2)

70
(1) The display of the monitor status dialog
4)3)2)1)
(2) The interpretation of the status display for the circuit monitor
Reference
Scan time
The maximum scan time of the sequence
program is displayed.
PLC status
The status of the PLC is displayed.
The execution status of the monitor
It is ﬂashing when the monitor is being
executed.
Memory type display
The memory type of the PLC is displayed.
1)
2)
3)
4)
Contact Instruction
Input contact
Type
X0: OFF X0: ON
NO contact
X000
Circuit open
X000
Circuit close
NC contact
X000
Circuit close
X000
Circuit open
1)
Out Instruction
Driving status
Type
Non-execution/
Non-drive
Execution/Drive
OUT instruction
Y000 Y000
SET instruction,
etc.
SET M0 SET M0
2)
The ON/OFF status of the device to be rest is displayed by the monitor using RST instruction.
Device status
Type
When device to be
reset is OFF
When device to be
reset is ON
RST instruction
RST M0 RST M0

71
Appendix 1.5 Editing the circuit
Appendix 1.5.1 Correcting the circuit
Make sure to set to "Write Mode" when amending the circuit.
Select from the tool bar. Select from the menu ([Edit]→[Write mode]).
Switch between "Ovrwrte" and "Insert"
• Set to "Ovrwrte" when correcting the already created circuit diagram.
• The new circuit will be inserted when the "Insert" mode is set to.
●
●
●
Point
It switches between
"Ovrwrte" and "Insert"
by pressing the key.Insert

72
1) Changing the number of the OUT coils and the contacts
[The circuit to be corrected]
The corrected result is displayed and the
circuit block is displayed in grey.
3)
4)
Double-click the part need to be corrected.1)
Conﬁrm the changes by pressing the F4
(Convert) key.
5)
X002
Y000
X000
X003
Y001
Y002
Y000
Change to
Change "Y001" to "Y002".2)
1) Double-click
2) Change "Y002" 3) Input the Enter key
F4 (Convert)
4) The corrected result is displayed

73
2) Adding lines
[The circuit where lines are to be added to]
The line reaching the dropped position is
added.
Locate the cursor on the position where the
OUT coil is to be added to and click on the
tool bar.
3)
4)
Click ( F10 ) on the tool bar.1)
X002
Y000
X000
X003
Y001
Y000
Y003
Add the vertical/
horizontal lines and
create the OUT coil
Locate the cursor on the upper right of the
desired vertical line to be added, and then
drag it until it reaches the desired position, and
then drop it.
2)
Input "Y3".
5)
6)
1) Click
2) Drag
beginning of the vertical chart to be added
5) Change "Y003" 6) Input the Enter key
The lines are added
4) The position of the cursor

74
(Convert) key
• Click on the tool bar again to ﬁnish the
operation.
8)
The circuit adding is ﬁnished and the circuit
block is displayed in grey.
7)
7) The circuit adding
is completed
F4 (Convert)

75
3) Deleting lines
[The circuit where lines are to be deleted]
The lines are deleted.
Delete the OUT coil by the Delete key.
3)
4)
Click Alt + F9 on the tool bar.1)
X002
Y000
X000
X003
Y001
Delete this
circuit
Y000
Y003
desired vertical line to be deleted, and then
drag it until it reaches the desired position, and
then drop it.
2)
1) Click
2) Drag
Locate the cursor on the upper right
of vertical line to be deleted
3) Delete the lines
4) Delete it by the Delete key

76
The deleted circuit block is displayed in grey.5)
(Convert) key.
operation.
6)
F4 (Convert)

77
Appendix 1.5.2 Inserting and deleting lines
1) Adding lines
[The circuit where a line is to be inserted into]
The line is inserted.3)
X002
Y000
X000
X003
Y001
Add this lineX001
Y000
Y002
Right click the mouse at any place, and select
[Insert line].
2)
A line is inserted above the line where the cursor
is located
Locate the cursor on the line below the one to
be inserted.
1)
Add a program in the inserted line.4)
Conﬁrm the changes by pressing the Convert
(F4) key.
5)
1) Move the cursor to the line
below the one to be inserted
Select "Insert line"
2)
Right click
the mouse
3) New line is inserted
4) Add a circuit
X001
Y002

78
2) Deleting lines
[ The circuit where a line is to be deleted ]
The line is deleted3)
Move to the line to be deleted1)
X002
Y000
X000
X003
Y001
Delete this line
X001
Y000
Y002
Right click the mouse at any place, and select
[Delete line]
2)
The line to be deleted is displayed in grey.
Conﬁrm it by pressing Convert (F4).
Point
1) Move the cursor to
the line to be deleted
Select "Delete line"
2)
Right click
the mouse
3) The line is deleted

79
Appendix 1.5.3 Cutting and copying (pasting) the circuit
1) Cut
[The circuit to be edited]
Move the cursor to the beginning of the circuit
to be cut.
1)
X002
Y002
X000
X004
Y004
X007
Y002
Y007
Cut this line
Drag it until it reaches the desired position,
and then drop it.
Select from the tool bar or select [Edit] →
[Cut] ( Ctrl + X ) from the menu, and execute
the cut.
2)
3)
The selected area is cut
The grey displayed part is remained when one
part of the circuit is cut. Conﬁrm it by the F4
(Convert) key after the circuit is amended.
4)
The cut and copy area1) Move the cursor to
the beginning of the
cut area
2) Drag it until it reaches the desired
position, and then drop it
3) Execute cut
4) The selected
area is cut

80
Continue to edit the circuit with the "cut" operation
performed in the previous steps.
Move the cursor to the beginning of circuit to
be copied.
1)
Drag it until it reaches the desired position,
and then drop it.
[Copy] ( Ctrl + C ) from the menu.
2)
3)
[Paste] ( Ctrl + V ) from the menu.
The grey displayed part is remained when one part of
the circuit is pasted. Conﬁrm it by the F4 (Convert) key
after the circuit is amended.
5)
Move the cursor to the position where to
paste.
4)
Switch by the Insert key
"Ovrwrte" mode : Pastes by overwriting in
the cursor position.
"Insert" mode : Pastes by inserting in the
cursor position.
Point
1) Move the cursor to the
beginning of the copy area
3) Execute
copy
2) Drag it until it reaches the desired
position, and then drop it.
4) Move the cursor to the
position where to copy
5) Finish copy/paste
Y000
X004
X000
X002
Y000
X002
Y000
Y000
X000
Y004
Copy this
line
Paste it to
this line

81
Appendix 1.6 Saving the created circuit
Appendix 1.6.1 Save as and save
If there are circuits not converted in the program, press Convert (F4) and save it.
Point
Select from the tool bar or select [Project]
→ [Save] ( Ctrl + S ) from the menu.
1)
Click Yes in the conformation dialog and
finish it.
If there is not sufficient space in the floppy disk to
save the project, temporarily save it to the hard
disk and then move it to the other floppy disk.
6)
Specify the storage destination for the project.
Specify the project name.
Specify the title describing the project
(optional).
Click Save .
2)
3)
4)
5)
Reference
1) Click
3) Specify the project name
2) Specify the storage
destination for the project
5) Click
4) Specify the title (optional)
6) Click
(When it is newly saved)
(When it is saved by overwriting)
Project saving is finished
The following characters cannot be used in the project name.
/ ,¥ ,> ,< ,* ,? ,” ,“ , | , : , ; ( ; , ¥ are only used to specify the driver)
Also, do not use “.” (period) at the end of the project name.
When the project name is specified with 8 or more characters by GX Developer (later than SW6D5-
GPPW), characters past the 8th character will not be displayed if read by the old versions (older than
SW2D5-GPPW) of GX Developer.
The project path plus its name is within 150 half-width characters (75 full-width characters).
The tile is within 32 half-width characters (16 full-width characters).
If there are spaces in the project path and project name, GX Developer cannot start normally even if
GPPW.gpj, ***.gps is double-clicked in the Explorer window.
If there are spaces in the project path and project name, open the project by starting GX Developer →
selecting [Project] → [Open project] from the menu.
●
●
●
●
●

82
Appendix 1.6.2 Saving the project as a new one
Select [Project] → [Save as] from the menu.1)
Specify the storage destination for the project.
Specify the project name.
Specify the title describing the project
(optional).
Click Save .
2)
3)
4)
5)
Click Yes in the confirmation dialog and
finish it.
6)
For the way to name the driver/path and the project,
see the previous page.
If there is not sufficient space in the floppy disk to
save the project, temporarily save it to the hard
disk and then move it to the other floppy disk.
If there are circuits not converted in the program, press Convert (F4) and save it.
Point
1) Click
3) Specify the project name
2) Specify the storage
destination for the project
5) Click
4) Specify the title (optional)
6) Click

83
Appendix 1.6.3 Reading the project
Select from the tool bar or select [Project]
→ [Open project] ( Ctrl + O ) from the menu.
1)
If another project is open at the reading operation, the project is closed.
If there are circuits not converted in the project or the project is not saved, the warning message is
displayed.
Reference
Select the storage destination of the project.
Select the project to be read.
Click Open and read the project.
2)
3)
4)
1) Click
3) Select the project name
4) Click
2) Select the storage
destination of the project.

84
Appendix 1.7 Necessary operation for the debug of the program
For connecting to PLC and the writing of the program, see "3.4Writing programs to PLC".
Appendix 1.7.1 Circuit monitor
Display the circuit, and monitor the conduction status of the contacts and the driving status of the coils
The ON/OFF status of the circuit and the
current value of the word device (timer,
counter and data register) are displayed in the
circuit monitor window.
Right click the window, select [Stop monitor] to
quit the circuit monitor.
In order to correct and write the program,
select from the tool bar or select [Edit] →
[Write mode] from the menu.
2)
3)
4)
Select from the tool bar or select [Online]
→ [Monitor] → [Monitor mode] from the menu.
1)

85
(1) the display of the monitor status dialog
4)3)2)1)
(2) The interpretation of the status display for the circuit monitor
Reference
Scan time
The maximum scan time of the sequence
program is displayed.
PLC status
The status of the PLC is displayed.
The execution status of the monitor
It is ﬂashing when the monitor is being
executed.
Memory type display
The memory type of the PLC is displayed.
1)
2)
3)
4)
Contact Instruction
Input contact
Type
X0: OFF X0: ON
NO contact
X000
Circuit open
X000
Circuit close
NC contact
X000
Circuit close
X000
Circuit open
1)
Out Instruction
Driving status
Type
Non-execution/
Non-drive
Execution/Drive
OUT instruction
Y000 Y000
SET instruction,
etc.
SET M0 SET M0
2)
The ON/OFF status of the device to be reset is displayed by the monitor using RST instruction.
Device status
Type
When device to be
reset is OFF
When device to be
reset is ON
RST instruction
RST M0 RST M0

86
Appendix 1.7.2 Device registration monitor
1) Registering optional devices
Register the optional devices in the monitor window and monitor the necessary part only.
Input the device number to be registered in the
Register device window.
Click [Register].
4)
5)
The device is registered in the monitor
window.
Click [Start monitor], and the value showing
the device action and the ON/OFF status of
the contacts and coils are displayed.
6)
7)
Set the circuit monitor status. (See Section
3.7.1.)
Select [Monitor] → [Entry data monitor] from
the menu. Or right click the circuit window and
select [Entry data monitor].
1)
2)
3) Click
Select "32 bit integer"
when you want to
nomitorthe device in
32 bits.
4) Input the device
5) Click
7) Click
Click [Register devices] in the "Entry data
monitor" window.
3)

87
Set to the status of the circuit monitor. (See
Section to 3.7.1.)
Select [Monitor] → [Entry data monitor] from
the menu. Or right click the circuit window and
select [Entry data monitor]. (See the previous
page)
Select [Window] → [Tile horizontally] from
the menu to display the "Circuit window"
and "Entry data monitor window" apposed
together. (Set "Entry data monitor window" to
the status of stop monitoring.)
The "Circuit window" and "Entry data monitor
window" are displayed horizontally.
1)
2)
3)
4)
2) Registering the devices displayed in the circuit monitor
Specify the area of the circuit diagram in the circuit monitor window and register all of the devices in the
area.
5) Click the start point of the circuit.
6) Click the end point while pressing
[Shift] key to select the area.
7) Click
The devices are registered to the monitor
window.
Click [Start monitor], and the value showing
the device action and the ON/OFF status of
the contacts and coils are displayed.
8)
9)
9) Click
Click the start point of the circuit.
Click the end point while pressing the [Shift]
key to select the area.
Drag the selected area to the "Entry data
monitor window".
5)
6)
7)

88
Appendix 1.7.3 Device batch monitor
Specify the start number and monitor the continuous devices.
Section 3.7.1.)
Select [Monitor] → [Device batch] from the
menu. Or right click the circuit window and
select [Device bath].
1)
2)
3) Input the device
The value showing the device action and the
ON/OFF status of the contacts and coils are
displayed.
4)
Input the start number of the devices to be
monitored in the "Device batch monitor"
window and then press the Enter key, and
then click [Start monitor].
3)

89
Appendix 1.7.4 Device test
1) Forced ON/OFF
Forcedly turn ON/OFF the bit devices of PLC (M,Y,T,C and so on). (The forced ON/OFF function of X is
not available.)
When PLC is running, the forced ON/OFF function can turn on or off the devices only for one scan and
the operations according to the sequence program are given priority. When checking the output, set
PLC to the STOP status.
Section 3.7.1.)
Select [Monitor] → [Device] → [Device test]
from the menu. Or right click the circuit
window and select [Device test].
1)
2)
Forced ON/OFF (Circuit monitor window)
The speciﬁed device can be forcedly turned on/off by double-clicking any bit device (contact, coil) in
[Circuit monitor window] while pressing the [Shift] key.
Reference
3) Input the device
4) Click
Input the device number to be forcedly turned
on/off.
• [FORCE ON]: Turns on the device.
• [FORCE OFF]: Turns off the device.
• [Toggle force]: Switches the ON/OFF status
of the device is switched each time it is
pressed.
3)
4)

90
2) Changing the current value of the word device
Change the current speciﬁed value of the PLC's word device (T, C, D and so on).
Section 3.7.1.)
Select [Monitor] → [Debug] → [Device test]
from the menu. Or right click the circuit
window and select [Device test].
1)
2)
3) Input the device
5) Click4) New value
Input the device number to be changed.
Input the a new value.
Click [Set].
3)
4)
5)

91
Appendix 1.7.5 Writing the program during RUN
Write the corrected part of the circuit to PLC when the PLC is running.
Less time is needed for the writing because of not transferring the entire program.
Adding the contact to the circuit on the left is
described as an example.
Display the circuit diagram and set it to write
mode ( ).
1)
It is impossible to write the program to PLC if the program before corrected in PLC is different from
the one in GX Developer. Verify it in advance, or transfer it by [Write to PLC] if not knowing whether
they are the same.
Caution
Add the contact.
The circuit block is displayed in grey.
2)
Pressing [Shift] and [F4] together, or select
[Convert] → [Convert (Write during RUN)]
from the menu.
3)
The message "RUN write processing has
completed." is displayed and click [OK].
5)
2) Add the contact
4) Click
5) Click
Write during RUN Shift+F4
Click [Yes] to conﬁrm the warning message
about conﬁrming the safety of the PLC
controlling changes due to the program
changes
4)

92
Appendix 1.8 Inputting comment
Appendix 1.8.1 Types of the comment
The following 3 types of the comments can be input.
Type Purpose
The number of
the characters
(full-width)
Remark
1) Device comment
The comment describing the role
and function of each device
16
It is necessary to set "Comment
capacity setting" for the parameter
when writing to PLC. "Comment range
setting" for the writing also needs to be
set.
2) Statement
The comment describing the role
and function of the circuit blocks
32
It is only the comment (peripheral) in
the GX Developer’s side. (It is not put in
PLC)
3) Note
The comment describing the
role and function of the output
instructions
16
It is only the comment (peripheral) in
the GX Developer’s side. (It is not put in
PLC)
[Comment Examples]
How to display the comment
Select [Display] → [Display comment] from the menu and then the comments are displayed.
Do the above operation again to stop comment displaying
●
●
Point
T5 NO contact exists at step10,
whereas T5 NC contact exists at step8.
3) Note
2) Statement
1) Comment
X000
Y000
Y000
T5
T7
Start
Lamp
Green
Conveyor
Stop
Time
START Circuit
Buzzer Time Setting
Lamp Green
2-second Timer
0
4
8
<The Start Btn truns on lamp >
<Buzzer rings awhile >
(Y000 )
Y000
A/S
A/S
1
T5
B/D
B/D
10
8
4
Lamp
Green
K20
(Y001 )
Buzzer
T5
2-second
Timer

93
Appendix 1.8.2 Operation for creating the device comment
1) How to input the device comment from the list
Click [Device comment] → [COMMENT] in the
project list.
1)
1) Click
Input the start number of the devices which
are to be commented in "Device name", and
click [Display].
Input comments in the "Comment" column.
• When inputting comments for another
device, Input the device number again
following step 2.
2)
3)
2) Input the device number
3) Input comments
Click from the tool bar and double-click the
circuit diagram symbol to be commented.
Input the comment in the "Enter symbol"
window and click [OK].
operation.
1)
2)
2) How to input the device comment from the circuit diagram
1) Double-click
2) Input the comment

94
How to input comments when creating a circuit
Reference
Continues during command write
Setting for writing the device comments to PLC
It is necessary to set "Parameter setting" and "Comment range setting" to write the device comments
to PLC.
Parameter setting
Select [Parameter] → [PLC parameter].
Set the "number of blocks" in the "Comment capacity" setting.
One block is equivalent to a 50-point comment, occupying the capacity of 500-step program
memory.
The capacity of the program
reduces according to the
reduction of the comment capacity.
Comment capacity setting
2) Comment range setting
Select [Device comment] → [Comment], and then the comment input screen is displayed.
Select [Edit] → [Setup comment range] from the menu.
Set the type and the range of the devices to be written to PLC in the Setup comment rang
dialog.
Comment
range setting
1)
●
●
●
●
●
Point
Select [Tool] → [Options] from the menu, Check
"Continues during command write" of the
[Comment input] box in the [Program common]
tab.
After configuring the settings as above, the
operation of the circuit input continues and the
"Enter symbol" window described in step 2) is
displayed, when the circuit is being created.

95
Appendix 1.8.3 Operation for creating the statement
Click from the tool bar, and double-click
anywhere of the circuit block which the
statement is to be written to.
Input the statement in the "Enter line
statements" window and click [OK].
operation.
1)
2)
Appendix 1.8.4 Operation for creating the note
Click from the tool bar, and double-click
the output instruction symbol which the note is
to be written to.
Input the note in the "Enter Note" window and
click [OK].
operation.
1)
2)
1) Double-click
2) Input the statement
2) Input the note
1) Double-click

96
Appendix 1.9 Operation for creating the program list
In GX Developer, the program can also be created by list.
Appendix 1.9.1 Displaying the list edit screen
Create a new project (See Section 3.2.2.) or
display the circuit of the existing project.
Select from the tool bar or select [View] →
[List display] from the menu.
1)
2)
Appendix 1.9.2 How to input instructions
Input the instruction language from step 0
sequentially.
The step number is added automatically when
instruction is input. (For the input procedures,
see the next page.)
1)
1) The list edit screen is displayed
3) The list edit screen
is displayed
Initial screen After list input
The list edit screen is displayed.
Click on the tool bar again or select [View]
→ [Circuit display] from the menu to return to
the circuit display.
3)

97
How to input the basic instructions and the applied instructions
A "space" is input between the instruction language, device number and operand.
●
[Examples for the basic instructions]
LD
OUT
LDI
AND
OUT
LD
OUT
OUT
[Examples for the applied instructions]
MOV
CMP
Connection and OUT instructions
The key operation when inputting/editing
• "Ovrwrte"/"Insert" mode switches by pressing the Insert key.
• An instruction can be deleted by the Delete key.
[Insert line] and [Delete line] operations can be done by the right click of the mouse
Reference
X0 Enter
Y0 Enter
X0 Enter
Y0 Enter
M0 Enter
M0 Enter
T0 K10 Enter
C0 K5 Enter
K1 D0 Enter
K20 D3 M10 Enter
Coil instructions for the timer and counter

98
Appendix 1.9.3 Checking the content of the list input
Conﬁrm that there are no errors in the program created by list input in the circuit display.
Select from the tool bar, or select
[View] → [Circuit display] from the menu.
1)
Check whether the circuit created by list input
is displayed.
2)
Select [Tools] → [Check program] to execute
the program check, and check whether errors
occur and the error steps.
3)

99
SFC Program Outline
Appendix 2

Jy997 d22101 b[1]

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